Silver or silver-plated metal is very sensitive to corrosion, especially by the sulphur-containing compounds often present in the atmosphere.
Processes for protecting such parts must be effective for a prolonged period of time while preserving the white appearance of the silver.
Various processes intended to protect these silver or silver-plated parts are known, such as chromating or applying a varnish.
Processes intended to protect silver are also known which consist in applying a rhodium or platinum coating.
Mention is made, among protective coatings based on non-noble metals, of the deposition of tin.
Thus, FR 1,097,672 describes an electrolytic deposition of tin in which the tin is deposited from an acidic alcoholic or aqueous solution additionally containing Cd, Zn, Al, Ag, Au or Pt.
Moreover, it is known to deposit coatings composed of a Cu--Sn--Zn alloy on nickel or copper or nickel-coated or copper-coated parts in order to confer the appearance of silver on the final product obtained. However, in this case, the deposition time is relatively long in order to confer a sufficient thickness on the Cu--Sn--Zn coating in order to completely mask the underlying metal and to imitate the "whiteness" of silver.